The weirdest conversations I've ever come across were all from this one person/character in one of my beloved text-based MUDs. Considering that I think cybering is for losers, there's a lot of it about, but I just ignore it. However, there was this female character who didn't get the message that I wasn't interested, and she kept making constant advances towards me. A lot of them were just insane and hilarious. I kept her around just for the entertainment value. XD Here's a few of her gems.
"You've only ever been with girls, right? Have you ever done it in the back door?"
"So, how do you feel about chicks with dicks?"
"Don't worry. I have both sexual organs."
"If you grip that sword any tighter, I'm going to get a bulge in my pants."
"My mom thinks you're cute..."
"Would you ever do a mother and daughter at once?"
"...How about a sister? We're not the same species, but..."
"You don't have a problem dating non-humans do you? That's just narrow-minded."
"I'm sorry. I didn't mean to snap at you."
"...Kiss and make up?"
"...Kiss me...down there...?"
I wish I were kidding, but I'm not. I think I must have died three times while she was in my party because I was laughing so hard. I like to call this, 'When roleplay goes bad...'